After surgery, to drain a fluid (liquid or gas generated by biological tissues or used for treatment) outward from the inside of a body, a medical drain tube (medical tube) as disclosed in Japanese Patent Application No. 4715504 is used.
As an example, in the pancreaticoduodenectomy, the medical drain tube is used for an anastomosis portion where the pancreas (pancreatic body and pancreatic tail) having the excised pancreatic head and the jejunum are anastomosed with each other. A trunk portion of the medical drain tube is caused to indwell after passing through the jejunum, and a distal portion of the medical drain tube is inserted into and caused to indwell the pancreas (main pancreatic duct), which is anastomosed with the jejunum. In this manner, the pancreatic juice generated inside the pancreas is drained out of the body through the medical drain tube from the main pancreatic duct.